The objective of our Cooperative Center for Translational Research on Human Immunology and Biodefense is to use the analysis of vaccine-induced and naturally acquired immunity to influenza A as a model for defining adaptive and innate immune mechanisms and antiviral protection in children and younger adults. The Clinical Core will be responsible for coordinating protocol design and implementation to maximize opportunities for parallel evaluations across Projects 1, 2, 3, obtaining human subjects approvals, and creating and managing the centralized database to record clinical data. The Clinical Core will coordinate distribution of relevant specimens to the participating laboratories and provide matched clinical data in coded form for analysis. Centralizing these functions is particularly important for protocols that involve children, to allow for the most efficient use of small volume blood samples. As the work proceeds, the Clinical Core database will facilitate comparative analyses of results obtained from the individual Research Projects. The Specific Aims of the Clinical Core are Aim 1: Protocol and Regulatory Support. To make the necessary IRB submissions for clinical studies, recruit and enroll adults and children to receive influenza or HBV vaccines or children and adults who have acute influenza A infection into clinical protocols, assure that subject rights are respected throughout the duration of their trial participation and provide follow-up to assure collection of complete sets of data from all subjects. Randomization codes and subject reimbursement payments will be provided by the Core. Aim 2: Clinical Data Management and Quality Management. Provide centralized clinical data management for Research Projects and other Cores using an electronic database with electronic data entry; implement a quality management plan to assure data integrity. These data will then be made available to the Research Projects, Bioinformatics and Genetics Cores for final data analysis. Aim 3: Sample Collection and Distribution. Blood and nasopharyngeal specimens will be collected by the Clinical Core phlebotomists or research nurses according to the specifications of each clinical study protocol, and delivered either to the CTRU laboratory or directly to Research Project staff.